Insufficient volume/pressure - Well? Plumbing? Softener?

[JCD]

The Scene (Problem Statement):

I recently bought and renovated a 1983 house with a well, and it is the first time I’ve owned a well. The renovations included a spa shower (Moen ioDigital) with four loops: two showerheads and two sets of dual bodysprays. The water volume/pressure is adequate at best, but after a few minutes the pressure drops substantially, which causes two problems: One is that it renders us unable to fully use all the water sprays; and Two is that the pressure drop “confuses” the valve controller and causes it to wildly cycle between hot and cold, which is a bigger issue!

I’ve hired several plumbers, several well drilling companies, and even a water softener company, and either they want to sell me a product without being able to explain if or how it will solve the problem, or they simply shrug and suggest I call one of the other trades…

Here are the details:

The Props:

Well Pump: age, brand and specs unknown. Controller reads STA-RITE, ½ HP, 3450 RPM, Model IP4C02. Comes into the house on a 3/4” line and goes to the pressure tank. Straight from the pump inlet, the pressure is about 22 gpm at 50 psi, and 13-15 gpm at 30 psi (per the water softener guy).

Pressure Tank: AMTROL 32 gallon tank, a couple years old. Pressure switch 40/60 psi.

Water Softener: Sear Kenmore 625.3484500, rated at 8 gpm service flow, circa 1987? Plumbed with 3/4” hard copper from the pressure tank, but goes through 9 elbows and 2 flex lines in the span of the ~15’ it takes to get to it. Output splits off a few places to feed the rest of the house, then feeds into the HWH.

HWH: GE SG60T12YVK00 50gal nat gas “high-recovery”, brand new. Cold supply tees in just above the inlet and feeds the upstairs bathroom via 3/4" PEX straight up about 20-25’ of head. Hot output from the HWH does the same.

Spa Shower: Moen ioDigital 3/4” valve with max flow rate of 17.5 gpm @ 45psi. Four loops: Two shower heads, and two loops with two body sprays each.

Other fixtures in the house: powder room (toilet and sink), bathroom (std shower, toilet, sink), kitchen sink, two outdoor spigots, future bathroom (shower, toilet, sink)

Only two adults in the house.​

The Actors:

The plumber says a second hot water heater will improve the water stability feeding the valve controller because it will double the amount of hot water available, and also act as a secondary storage/pressure tank.

The plumber also says that the cold water supply line for the bathroom should NOT be tapped near the HWH because it will “siphon” the cold supply from being able to flow into the HWH. This sorta makes sense, though I don’t understand how tapping the cold supply line in ten feet away will really change that.

The plumber also suggested a larger pressure tank and “tweaking” the cutover settings (which are already set to 65 psi). When I probed him on how he sized the tank requirement, he punted and said call a well company… which I then did.

The well driller says that I need a variable speed pump. I asked him about cycle-stop-valves and he said, nah, I’d need a pump that can keep up. He said the water softener looks like a problem too, and suggested I call a water softener company… which I did.

The water softener guy says the softener is likely constructing flow because it is ancient old, and because the supply line feeding it has 9 elbows in it, plus 2 flex lines. He suggests running a 1” line right from the well pressure tank into a new water softener (without all the elbows), and then installing a manifold block and re-running all the plumbing lines in a home-run from this manifold.​

The Happy Ending to the Story:

??
Everyone wants to sell me something but nobody can really demonstrate that they understand the nature of the problem and why what they sell me will resolve it. I don’t have $10,000 to spend on a shotgun menu of things that may or may not fix the problem, but until I understand exactly what the cause of the problem is, I can’t make a smart investment in solving it.

I’m hoping desperately that one of you guys can help.

 

[Craigpump]

The VERY first thing to do is determine whether or not your well and pump can keep up to the demand. A simple yield test done at the top of the well will do that.

You say the tank is a 32 gallon Amtrol that I interpret as being a wx203, which is way too small for a pump that moves anything over 5-7 gpm. I like to see a tank that will provide a minimum of 2 minutes run time, although I know that isn't always realistic due to space and economics. In your case, you should have a wx350.

Forget the electronic "constant pressure" BS, I see more junk controllers laying around than I can count. I think a better way to go would be with a Cycle Stop valve installed on your present tank provided the well and pump can meet your demands.

All water treatment equipment creates some reduction in pressure, but that is easily rectified by increasing the cut in/ cut out pressure on the system.

 

[Sponsor]

 

[Reach4]

Comes into the house on a 3/4” line and goes to the pressure tank. Straight from the pump inlet, the pressure is about 22 gpm at 50 psi, and 13-15 gpm at 30 psi (per the water softener guy).

I think you you are saying that you have "3-wire" submersible pump, and when you say "pump inlet" you mean the output of the pump after it goes through the piping and into the house.

You can get a water pressure gauge that uses a garden hose thread. Some have a "lazy hand" AKA "tattletale" that will record the peak pressure, and some of those will let you wrap the hand around to record the minimum pressure. One or 2 of those could be useful in diagnosis. You have the garden hose thread not only on your hose spigots, but on your washing machine inlets, the side of your water heater, and maybe on your laundry sink.

Also you want to have a water hardness kit to check on your water softener effectiveness. The Hach 5-B is well respected, accurate and easy.

 

[LLigetfa]

Straight from the pump inlet, the pressure is about 22 gpm at 50 psi, and 13-15 gpm at 30 psi (per the water softener guy).

OK, so which is it? 22 GPM at 50 PSI or 13 GPM at 30 PSI? It cannot be both! As craigpump said, that is the first bit of misinformation that needs to be cleared up. Determine the real GPM/PSI pump curve up to about 70 or 80 PSI so we can know if increasing the PSI can overcome some of the friction loss.

but after a few minutes the pressure drops substantially...

I think you need to get out a stopwatch and/or monitor various points along the path, because that statement seems implausible given what other info you provided. I cannot deduce where within your system you would have a few minutes worth of pressure reserve.

The plumber says a second hot water heater will improve the water stability feeding the valve controller because it will double the amount of hot water available, and also act as a secondary storage/pressure tank.

If the plumber really said that, then fire him. A HWT can provide additional heat storage but will NOT act as a secondary pressure tank. A pressure tank utilizes trapped air to "store" pressure.

As to the comment the plumber made of where to tap into the cold line, unless you misquoted him it is hogwash. Tapping the cold closer to the source will "steal" more of the water from reaching the HWT. You will get less variation between hot and cold pressures by tapping both of them closer to the HWT.

 

[JCD]

@craigpump:

Thank you for your comment about the tank. This seemed a plausible - and simple - way to improve things, but when I asked questions about the sizing, they had no clue so I got the sense they were just guessing. (Sheesh, I can do that!) My first question to them was: if a larger pressure tank is good, and you quoted upgrading to an 86-gal tank, why don't we go to the largest size available - 119-gallon? He wouldn't answer. Anyway, upgrading the tank seems logical, direct, and relatively low-cost, low-fuss, so if this is a strategy to try, I'm all for it.

I guess I'll call yet another company to come out and do a yield test.​

@reach4:

I do have a garden hose thread Watts water pressure gauge, so I can plug that in. No laundry tub, so the only places I can screw it on are at the pressure tank and at the outside spigots, but I'll do that and report back.
​

@LLigetfa, you wrote:

Tapping the cold closer to the source will "steal" more of the water from reaching the HWT. You will get less variation between hot and cold pressures by tapping both of them closer to the HWT.

Okay, then if I am understanding you, that fact that BOTH the hot and cold supply lines to the shower feed off the top of the HWH is okay?​

As to the comment about the pressure drop, I can time it if it would help, but that's what happens. I can have all four loops of the spa shower running and for the first few minutes they are reasonable robust, then after some minutes (I don't know, maybe it's closer to 5? I will time it) the pressure/volume drops and the body sprays, for example, just kind of dribble out limply rather than spray.

I was thinking this was either because the pressure tank was exhausted, or because the well pump is struggling to keep-up and re-pressurize the system. Let me add that when the shower valve goes wonky, if I pause the shower control (it literally has a "pause" button) for a few seconds and then turn it back on, it seems to "re-calibrate" to the temperature and no longer jumps wildly between hold and cold - but the pressure remains low.

If it helps the discussion, I do think (in my neophyte view) that the well pump seems to cycle on/off a lot...?
​

Thanks all, very much for the leads/replies!

 

[Craigpump]

You might want to contact the local health dept for the well completion report so you can compare what the well was yielding when drilled vs what it makes today.

 

[LLigetfa]

As to the comment about the pressure drop, I can time it if it would help, but that's what happens. I can have all four loops of the spa shower running and for the first few minutes they are reasonable robust, then after some minutes (I don't know, maybe it's closer to 5? I will time it) the pressure/volume drops and the body sprays, for example, just kind of dribble out limply rather than spray.

I was thinking this was either because the pressure tank was exhausted, or because the well pump is struggling to keep-up and re-pressurize the system.​

​

Your pressure tank has just over 8 gallons of drawdown so it should not take minutes to deplete it with a bunch of body sprays. A single typical low-flow showerhead would be 2.5 GPM. I have no idea what GPM you may be using.

There is a possibility that the GPM from the well cannot keep up with the draw. If the well is slow to recover, the GPM will move down the curve as the head increases.

Most pressure gauges with a tattler hand can be spun around to hold the low mark instead of the high. You would be better off however personally observing the system under load.

 

[Terry]

The Moen ioDigital is using quite a bit of water. I don't think a single 50 is going to last very long. Normally you run those with a 75 or larger. I was considering running two tankless units, which would have meant a larger gas meter to keep up with demand.

The picture below is a 379,000 BTU tankless with an electric tank for the recirc that I found in a customers garage.

Something like this would be nice. 379,000 BTU tankless.

A larger standard water heater tank doesn't help with flow, but does help to store already heater water. If the pump doesn't keep up, it won't help that.

Filters can be a drap on the system.
Here is a home with 10 filters, five on each line that combine at the end.

Here my son Jamie is changing all ten filters.

 

[JCD]

@craigpump:

As to the well completion report… yeah, I called the County out here and they didn’t have anything in their records. When I bought the property, I got a rudimentary well inspection report, but it wasn’t that helpful; it just had the clearance for lack of e-coli, etc.​

@LLigetfa:

Given the ioDigital system is capable of pushing out 17.5 gpm max, I’m pretty sure I’m running close to that. If a single “low-flow” showerhead is 2.5 gpm, well, I basically have six of those – and I doubt mine are “low flow” in any case as I always remove the flow restrictors anyway! So I have no doubt that I’m running at least 15 gpm, if not maxing out at the 17.5 gpm capability of the ioDitial valve controller.

But your comment about the gpm from the well not keeping up seems sensible. This is where the yield test comes in, right?​

@Terry:

Yeah, I know the 50-gal HWH is outgunned – though oddly enough I don’t really seem to drain it with the shower. Where I DO drain it is when I fill the 146-gallon whirlpool tub – and that’s why I was looking at a second HWH in the first place. That (the quantity of hot water) seemed to be a secondary issue to the water flow/pressure in the shower. But as to the quantity of hot water, the plan is to install a second 50-gal HWH in parallel to solve that issue.

Do you think a tankless is a better solution to this part of the problem?​

@All:

I did some timing tests today, and I can confirm that the starting pressure in the line is 40psi. Then when I run water, the pump kicks in until the pressure gets to about 65psi (which takes almost exactly two minutes). Then off until it drifts back to 40psi, then on again for two minutes until it hits 65psi… repeat. I did this for about ten minutes and during that time the shower temp did not go wonky. It’s strange because sometimes it does, and sometimes it doesn’t. We have only the two of us in the house, and showers tend to be a singular event in terms of water draw (i.e., it’s the only thing happening: no dishwasher, no other running water, etc), so I’m not sure why sometimes it happens and sometimes it doesn’t?

Photo attached:

 

[Terry]

People I buy from prefer two tanks to a tankless when it comes to filling a tub.
The most I can get out of my 199,000 BTU tankless with 50 degree incoming water is five gallons a minute at 120 degrees. In Seattle.

An ioDigital from a customers home.

 

[LLigetfa]

For high GPM, you need a lot of tankless. As for tanks, some folk will raise the temp setting and then blend the output with a tempering valve. Some will even tap into the hot before the tempering valve for the dishwasher. Not all dishwashers do a good job of heating the water.

 

[JCD]

@Terry:

Thanks! I'll stick with the second tank then. I'm in Minnesota, and it gets, ahh, kinda cold here sometimes.​

@LLigetfa:

I have my tank set at the highest setting. I figure I can temper it with the cold as needed, and that way my starting temp is at least as high as it can go. No kids in the house, so we're not worried about scalding.

My dishwasher pulls right off the hot at the top of the tank. Is this not advisable???​

 

[Reach4]

Some will even tap into the hot before the tempering valve for the dishwasher.

Also for the clothes washer.

In my inexperienced opinion, having more than one tempering valve, located closer to point of use, would often be better. One advantage would be hot water sooner for the sinks. More expensive than one for the whole house, however -- ~$100 for just the mixing valve. Plus I guess they are a point of failure.

 

[LLigetfa]

Risk of scalding is not to be taken lightly. Even if there are no kids, there may be houseguests.

 

[Valveman]

I think your problem is that you have a 10 GPM, 1/2HP pump. In a really shallow well it can pump 15 GPM, but can in no way produce 17.5 GPM at 45 PSI. You would need at least a 15 GPM, 3/4HP pump, which will only deliver that much if the water level in the well is less than about 30'. If the water level is deeper than 30' you will need even larger than a 3/4 HP.

 

[JCD]

@valveman:
Thank you. Your response seems quite simple - which is very appealing in this whole mess! I'll call around and get quotes from a few additional well companies to see if they can quote an intelligent response.

Frankly, I'm surprised that they didn't just say something like this! Either they don't want the work, or maybe they just really want to sell an expensive variable speed pump? From what I've been reading and trying to educate myself... the VSP's seem problematic and expensive not only to buy but also to maintain.

This has been very frustrating because the reason I hire someone is because they have expertise and experience that I don't possess and it makes sense to pay for that. But when I embark on this and all the companies I talk to seem to not know and just be guessing, then I end-up having to do all the work myself; I'm not a *&@%! well or plumbing professional, so why does it seem I know more than these guys?! It's maddening.

 

[Reach4]

If you re-read post #2 on this thread, I think you will find that of interest too.

 

[Craigpump]

JCD, I hate to say this, but a lot of companies pay their guys commissions and emphasize sales and BS not nessecarily good diagnostics..

 

[Valveman]

“Buyer beware”. Educate yourself or suffer the consequences. Most “professionals” in all professions are simply parts changers. Few even know how to diagnose. They just keep changing parts until they get it working, or you stop paying.

You have listed pretty much everything we need to know to figure the size of pump you need, except the depth to water and/or pump setting. You are already lifting at least 25’ to the second floor. Add any depth to water in the well and you don’t have enough pump to do what you want to do.

When you get a large enough pump to do the high volume demands, then you will need a Cycle Stop Valve to make it handle the low volume demands without cycling itself to death. Water comes from the pump, not the tank. When you have a CSV to control a large pump, a small pressure tank is all you need.

CSV’s were designed to replace Variable Speed Pumps or VFD’s, and have been doing so successfully since 1993. The real professionals, who are not just “parts changers”, know this. But unfortunately real professionals are becoming fewer and farther between.

 

[JCD]

Thank you all so much for your replies and guidance!